“WASHINGTON — President Trump on Tuesday ousted his secretary of state, Rex W. Tillerson, extending a shake-up of his administration, 14 months into his tumultuous presidency, and potentially transforming the nation’s economic and foreign policy.

Mr. Trump announced he would replace Mr. Tillerson with Mike Pompeo, the C.I.A. director and former Tea Party congressman, who forged a close relationship with the president and is viewed as being more in sync with Mr. Trump’s America First credo. …

His profound disagreements with the president on policy appeared to be his undoing: Mr. Tillerson wanted to remain part of the Paris climate accord; Mr. Trump decided to leave it. Mr. Tillerson supported the continuation of the Iran nuclear deal; Mr. Trump loathed the deal as “an embarrassment to the United States.” And Mr. Tillerson believed in dialogue to resolve the North Korean nuclear crisis, but Mr. Trump repeatedly threatened military options.”

Mike Pompeo is a neocon who has called for regime change in Iran and North Korea. Rex Tillerson supported negotiations with North Korea and keeping the Iran deal. That’s the crux of the matter. Tillerson has been checking Trump’s worst hawkish instincts on foreign policy.